1. Field of the Invention
The present invention relates generally to the fields of interventional radiology, vascular surgery, cardiology, oncology and medical devices. More specifically, the present invention relates to a novel tourniquet and novel methods for its use.
2. Description of the Related Art
The use of systemic thrombolytic agents to treat deep vein thrombosis (DVT) has been reported previously..sup.1-5 While these investigations have demonstrated a certain degree of efficacy, the combination of high doses of a thrombolytic agent and the prolonged infusion times necessary to lyse venous clots have raised different safety concerns and limited acknowledgment of thrombolytic therapy as a viable treatment for deep vein thrombosis..sup.6 This method has had limited success in treating extremity deep vein thrombosis because collateral pathways become the preferred routes of venous outflow, and relatively little thrombolytic agent reaches the thrombus. However, because early clot lysis and re-opening of occluded veins can preserve venous valves and thus prevent or mitigate the development of chronic venous insufficiency,.sup.7,8 investigators have persevered in their attempts to discover safer ways to lyse deep venous thrombi. Early lysis of arterial occulsions has been achieved by using local delivery, instead of systemic infusion of the thrombolytic agent..sup.9-12 Bleeding complications have remained low compared to systemic infusions.
Using this same treatment philosophy, a few preliminary investigations have successfully used local catheter-directed delivery of a thrombolytic agent to lyse venous clots in the subclavian/axillary veins,.sup.13-17 and more recently in the iliofemoral segment of the lower extremity..sup.18-24 The results from these preliminary trials have shown improved efficacy and safety of locally-delivered thrombolytic therapy for the treatment of deep vein thrombosis. Thrombus not in easy reach of catheters, however, has not been easily and successfully treated.
The prior art is deficient in the lack of effective means of treating deep vein thrombosis in which the thrombus can not be easily treated using a catheter. The present invention fulfills this longstanding need and desire in the art.